如何使用2个条件属性对python列表进行排序 [英] How to sort a python list using 2 conditional attributes

问题描述

让我们说我要对看起来像这样的列表进行排序:

Lets say I want to sort a list that looks like this:

arr = ['45621', '78124', '24613']

上面的列表存储了公司中各个员工的ID.我不想仅根据ID进行排序，而是使用以下字典基于与ID对应的属性进行排序:

The above list stores the IDs for various employees at a company. I don't want to sort based on the IDs alone, but based on attributes that correspond to the IDs, using the following dictionary:

employees = {
    '45621' : { 'rating' : 3, 'hours_worked' : 42 },
    '78124' : { 'rating' : 4, 'hours_worked' : 78 },
    '24613' : { 'rating' : 3, 'hours_worked' : 51 }
}

所以它是这样的:如果雇员的rating较高，则他/她的ID将排在第一位.但是，如果有2名员工具有相同的rating，则我们将hours_worked进行比较，那么工作更多的人将排在其他人之前.

So its something like this: if an employee has a higher rating, his/her ID will come first. However, if 2 employees have the same rating, then we compare the hours_worked, and whoever has worked more will come before the other.

现在，我正在考虑2种不同的排序方法:插入和合并.我从网上编辑了一些代码示例，但是我正在努力比较第二个条件，即算法的2个等级相等.例如，我的插入排序的编辑版本如下所示:

Right now, I am thinking about 2 different sorting methods: insertion, and merge. I edited a few code samples from the web, but I am struggling to compare the second condition, that is, when 2 ratings are equal for the algorithms. For instance, the edited versions of my insertion sort looks like this:

InsertionSort

def insertionSort(arr):
    for i in range(1, len(arr)): 
        key = employees[ arr[i] ]['rating']
        j = i-1
        # Falls apart after this part
        while j >=0 and key < arr[j] : 
            arr[j+1] = arr[j] 
            j -= 1
        arr[j+1] = key 

合并排序似乎更加复杂，但是我试图至少理解一个问题.

The merge sort seems even more complex, but I am trying to at least understand one to get an idea.

对这些排序方法的任何帮助将不胜感激.谢谢.

Any help with these sorting methods will be greatly appreciated. Thanks.

注意:我不想使用内置的排序机制，因为这主要是为了学习，所以不是重复的.

Note: I don't want to use a built in sorting mechanism, as this is mainly for learning, so it is not a duplicate.

推荐答案

您可以基于自定义键使用python list.sort或sorted:

You can use python list.sort or sorted based on a custom key:

arr = ['45621', '78124', '24613']

employees = {
    '45621' : { 'rating' : 3, 'hours_worked' : 42 },
    '78124' : { 'rating' : 4, 'hours_worked' : 78 },
    '24613' : { 'rating' : 3, 'hours_worked' : 51 }
}

arr.sort(key=lambda x: (employees[x]["rating"], employees[x]["hours_worked"]))
print(arr)

结果:

['45621', '24613', '78124']

此外，由于您首先需要价格更高的轮胎，因此您应该颠倒顺序.

Also, since you need the ones with higher ranting first, you should reverse the order.

arr.sort(key=lambda x: (employees[x]["rating"], employees[x]["hours_worked"]), reverse=True)

这里有一个在线示例

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